CN114607701A

CN114607701A - Actuator

Info

Publication number: CN114607701A
Application number: CN202210177825.5A
Authority: CN
Inventors: 吉田达矢
Original assignee: Sumitomo Heavy Industries Ltd
Current assignee: Sumitomo Heavy Industries Ltd
Priority date: 2015-03-31
Filing date: 2016-03-08
Publication date: 2022-06-10
Also published as: KR20170134368A; EP3279486B1; US10371279B2; JP2021099165A; JP7122423B2; JPWO2016158229A1; TW201636523A; CN107429738A; KR102415241B1; WO2016158229A1; EP3279486A4; US20180010709A1; TWI589802B; JP6893170B2; EP3279486A1

Abstract

The invention provides an actuator. The actuator (10) is provided with: a guide (12) extending in one direction; and a slider (20) that is movable in the axial direction relative to the guide (12). One of the guide (12) or the slider (20) has a concave cross section, the other is constrained by three faces constituting the concave cross section, and the slider (20) is guided by the guide (12).

Description

Actuator

The present application is a divisional application of the chinese invention patent application having an application date of 2016, 3/8, an application number of 201680015987.1, and a name of "actuator".

Technical Field

The present invention relates to an actuator that moves while a slider is guided by a guide.

Background

Actuators used in a vacuum environment require that the vacuum chamber not be contaminated. As such an actuator, a pneumatic actuator is known (for example, patent document 1). The pneumatic actuator is configured to smoothly move the slider with respect to the guide shaft by ejecting compressed gas from an air cushion provided in the slider. The pneumatic actuator has: there are various advantages that fine impurities from lubricating oil or sliding surfaces are not generated, and the actuator does not generate heat, unlike an actuator using a rolling bearing or a linear guide.

Prior art documents

Patent document

Patent document 1: japanese patent No. 4443778

Disclosure of Invention

Technical problem to be solved by the invention

The structure of a previously known pneumatic actuator is as follows: the four surfaces of the rectangular cylindrical slider constrain a guide shaft having a rectangular cross section. Actuators of this structure exist: the guide shaft has several manufacturing problems, such as high manufacturing cost and complicated assembly and adjustment of the guide shaft by the slider.

The present invention has been made in view of such circumstances, and an object thereof is to provide a simple structure of an actuator in which a slider is moved while being guided by a guide.

Means for solving the technical problem

An actuator according to an embodiment of the present invention includes: a guide extending in one direction; and a slider movable in an axial direction with respect to the guide, wherein at least one surface of the guide is opened, the slider has an air cushion for ejecting compressed gas and a pneumatic servo chamber for driving the slider, and the slider is guided by the guide in a state of being floated with respect to the guide.

The term "one surface is opened" includes both a case where one surface is opened as a whole and a case where a part of one surface is opened.

The guide may have a concave section, the slider may be configured to be constrained by three surfaces constituting the concave section, and the slider is guided by the guide in a state of being floated with respect to the guide.

The guide may have a polygonal cross section, the slider may be configured to be constrained by one of a plurality of faces constituting the polygonal cross section, and the slider is guided by the guide in a state of being floated with respect to the guide.

According to these embodiments, compared to the actuator of the conventional structure in which the four surfaces of the slider restrain the guide shaft, the structure in which one surface of the guide is opened is adopted, and therefore the structures of the guide and the slider can be simplified.

A magnetic preloading mechanism may be provided between the slider and the guide, which exerts a downward force on the slider on the basis of a magnetic force. This ensures the bearing rigidity of the actuator.

An actuator according to another embodiment of the present invention includes: a guide extending in one direction; and a slider movable in an axial direction with respect to the guide, wherein at least one surface of the guide is opened, the slider has an air cushion for discharging compressed air and an exhaust groove for discharging compressed air discharged from the air cushion, and the slider is guided by the guide in a state of being floated with respect to the guide, and the exhaust groove includes a portion extending in the axial direction.

According to these embodiments, compared to the actuator of the conventional structure in which the four surfaces of the slider restrain the guide shaft, the structure in which the surfaces of the guide are opened is adopted, and therefore the structures of the guide and the slider can be simplified.

An actuator according to still another embodiment of the present invention includes: a guide extending in one direction; a slider movable in an axial direction with respect to the guide, wherein one of the guide or the slider has a concave cross section, the other is constrained by three faces constituting the concave cross section, and the slider is guided by the guide.

According to this embodiment, compared to the actuator of the conventional structure in which the four surfaces of the slider restrain the guide shaft, the guide or the slider has a structure in which one surface is opened, and therefore, the structures of the guide and the slider can be simplified.

The slider may be configured to have an air cushion that ejects compressed gas, and the slider may be guided by the guide in a state of being floated with respect to the guide. Thus, even in the case of the pneumatic actuator, the structures of the guide and the slider can be simplified.

The slider may further have an exhaust groove for exhausting compressed air ejected from the air pad. The vent slot may include a portion extending in an axial direction. Thus, even in a vacuum environment, a pneumatic actuator having a structure in which one surface of the guide or the slider is opened can be used.

The slide may have a pneumatic servo chamber extending in the axial direction. The guide may have a partition wall that enters the pneumatic servo chamber to divide the pneumatic servo chamber into two areas. The slider is movable in the axial direction relative to the guide by supplying compressed gas to one of the two regions of the pneumatic servo chamber and discharging the compressed gas from the other region.

In addition, any combination of the above-described constituent elements, and alternative embodiments of the constituent elements and expressions of the present invention among apparatuses, methods, systems, and the like are also effective as embodiments of the present invention.

Effects of the invention

According to the present invention, the structure of the actuator that moves while the slider is guided by the guide can be simplified.

Drawings

Fig. 1 is a schematic perspective view of a pneumatic actuator according to an embodiment of the present invention.

Fig. 2 is a perspective view of a slider constituting the pneumatic actuator.

Fig. 3 is an axial cross-sectional view of the pneumatic actuator taken along line a-a in fig. 1 and 2.

Fig. 4 is a sectional view of the pneumatic actuator taken along line B-B in fig. 1 for explaining the operation principle of the pneumatic actuator.

Fig. 5 is an axial cross-sectional view of a pneumatic actuator according to a modification.

Fig. 6 is an axial cross-sectional view of a pneumatic actuator according to another modification.

Fig. 7 is an axial cross-sectional view of a pneumatic actuator according to still another modification.

Fig. 8 is an axial cross-sectional view of a pneumatic actuator according to still another modification.

Fig. 9 is an axial cross-sectional view of a pneumatic actuator according to still another modification.

Fig. 10 is an axial cross-sectional view of a pneumatic actuator according to still another modification.

Detailed Description

In the following, the same or equivalent constituent elements and components are denoted by the same reference numerals in the drawings, and redundant description thereof will be omitted as appropriate. In the drawings, the sizes of the components are shown enlarged and reduced as appropriate for the sake of understanding. In the drawings, parts of the components that are not essential to the description of the embodiments are omitted.

Fig. 1 is a schematic perspective view of a pneumatic actuator 10 according to an embodiment of the present invention. The pneumatic actuator 10 includes: a guide member 12 extending in one direction and formed in a concave shape in cross section; a rectangular parallelepiped slider 20 guided by the guide 12 and movable in the axial direction along the guide 12. The guide 12 has a bottom wall 37, a 1 st side wall 38, and a 2 nd side wall 39, and both ends and a middle portion of the bottom wall 37 are supported by a base not shown.

The slider 20 has a cover 40. The cover 40 closes an opening of a pneumatic servo chamber 28 (described later) formed in the slider 20. In addition, if the pneumatic servo chamber 28 is formed not to penetrate the slider 20, the cover 40 is not necessary. The slider 20 is accommodated inside the guide 12 having a concave shape with a slight gap from the guide 12. As will be described later in detail, the slider 20 can smoothly move along the guide 12 by ejecting compressed gas (for example, air) from an air cushion provided in the slider 20.

The pneumatic actuator 10 is used for driving a movable stage in a device operating in a vacuum chamber such as an electron beam exposure device. In the case of use with an electron beam exposure apparatus, since the guide 12, the base, and the slider 20 are made of a non-magnetic material (e.g., ceramic), since the pneumatic actuator is a magnetic material and may affect the trajectory of the electron beam.

For example, the pneumatic actuator 10 does not generate fine impurities from a lubricating oil or a sliding surface, as compared with a slider using a rolling bearing or a linear guide, and is therefore suitable for an electron beam exposure apparatus used in a vacuum environment, for example.

Fig. 2 is a perspective view of the slider 20 as viewed from below, and fig. 3 is an axial sectional view of the pneumatic actuator 10 taken along the line a-a in fig. 1 and 2. Among the surfaces of the slider 20 constituting the substantially rectangular parallelepiped shape, the surfaces facing the concave guides 12 (i.e., the bottom surface 22, the 1 st side surface 24, and the 2 nd side surface 26) are formed with a plurality of air pads 30. The air cushion 30 discharges high-pressure gas supplied from an unillustrated gas supply system to form a high-pressure gas layer in a minute gap between the slider 20 and the guide 12, thereby floating the slider 20 from the guide 12. A pneumatic servo chamber 28 for driving the slider 20 is formed in the central portion of the slider 20.

Exhaust grooves

32, 34, and 36 for differential exhaust are formed in the edges of the bottom surface 22, the 1 st side surface 24, and the 2 nd side surface 26 of the slider 20 so as to surround the plurality of air pads 30. Accordingly, the

exhaust grooves

32, 34, 36 each include a portion extending in the axial direction of the slider 20. The exhaust groove 32 is open to the atmosphere. The exhaust groove 32 may be connected to an exhaust pump (not shown). The

exhaust grooves

34 and 36 are connected to an exhaust pump (not shown) for setting the pressure in the exhaust grooves to a low vacuum pressure level and a medium vacuum pressure level, respectively, and discharge the compressed gas supplied from the air pads 30 and the pneumatic servo chamber 28 of the slider 20 to the inside space to the outside. Thereby, leakage of compressed gas from the gap between the guide 12 and the slider 20 is prevented, and therefore, the pneumatic actuator can be used even under a vacuum environment. In addition, when the pneumatic actuator 10 is used in an atmospheric pressure environment,

such exhaust grooves

32, 34, 36 need not be provided.

In the case where the guide 12 is formed in a concave shape, the upper end of the 1 st side wall 38 and the upper end of the 2 nd side wall 39 of the guide 12 are easily deformed in a direction in which the interval therebetween becomes larger (i.e., the upper side is enlarged) according to the load capacity of the air cushion 30 disposed on the side surface of the slider 20. This may not ensure desired bearing rigidity. Therefore, it is preferable to dispose the air cushion 30 on the side surface of the slider 20 as close to the bottom surface 22 side as possible.

Fig. 4 is a sectional view of the pneumatic actuator along the line B-B in fig. 1 for explaining the operation principle of the pneumatic actuator 10. In fig. 4, the clearance between the guide 12 and the slider 20 and the clearance between the partition wall 13 and the pneumatic servo chamber 28 are exaggeratedly drawn. In practice, the size of these gaps is, for example, on the order of a few micrometers. As shown in fig. 4, a partition wall 13 partitioning the pneumatic servo chamber 28 of the slider 20 into two

servo chambers

28A and 28B in the axial direction is fixed to the guide 12. An air supply system 17A for discharging compressed air from servo chamber 28A or feeding compressed air into servo chamber 28A is connected to servo chamber 28A, and an air supply system 17B for discharging compressed air from servo chamber 28B or feeding compressed air into servo chamber 28B is connected to servo chamber 28B. The gas supply system 17A includes a servo valve 16A and a compressed gas supply source 18A, and the gas supply system 17B includes a servo valve 16B and a compressed gas supply source 18B.

When the compressed air is supplied to the air cushion 30, the slider 20 slightly floats with respect to the guide 12. Here, for example, when compressed air is supplied to the servo chamber 28A and compressed air is discharged from the servo chamber 28B, the partition wall 13 functions as a piston to move the slider 20 in the left direction in fig. 4. By controlling the opening degree of the

servo valves

16A and 16B in this manner, the slider 20 can be moved to an arbitrary position with respect to the guide 12.

As described above, according to the present embodiment, a structure is adopted in which the substantially rectangular parallelepiped slider slides in the guide having a concave cross section, instead of the slider that restrains the four surfaces of the guide. In this configuration, the guide can be supported at a plurality of positions, rather than being supported only at both ends thereof, and therefore, the flexural rigidity of the guide can be easily ensured, and the cross-sectional area of the guide can be reduced as compared with a guide shaft having a square cross-section. Therefore, the guide can be downsized and can be reduced in cost. Further, since the slider can be formed in a flat structure, the installation height of the pneumatic actuator can be reduced. Further, since the slider does not need to be formed in a cylindrical shape, the assembly adjustment of the slider to the guide can be simplified. Further, since the slider and the guide can be made as an integral structure, the number of components can be reduced.

In order to increase the bearing rigidity of the pneumatic actuator, a magnetic pretensioning mechanism may be provided. Fig. 5 is an axial cross-sectional view of the pneumatic actuator 10' according to this modification. Since the components denoted by the same reference numerals as those in fig. 3 in fig. 5 have the same configurations as those in fig. 3, the description thereof will be omitted.

The magnetic preload mechanism 48 applies a downward force to the slider 20 based on the attractive force of the magnet. The slider 20 is provided with an L-shaped support member 42 extending from the upper surface of the slider 20 toward both side walls of the guide 12. A magnet 44 is provided on the lower surface of the support member 42, and a soft magnetic material 46 is provided on the upper portion of the 1 st side wall 38 and the upper portion of the 2 nd side wall 39 of the guide 12, so that the magnet 44 and the soft magnetic material 46 attract each other. This can improve the bearing rigidity of the pneumatic actuator.

When the pneumatic actuator 10 is used together with an electron beam exposure apparatus, a leakage magnetic field from the magnet 44 may affect the trajectory of the electron beam. Therefore, it is preferable to magnetically shield the periphery (the portion indicated by the broken line C in fig. 5) of the magnet 44 and the soft magnetic material 46 to suppress the leakage magnetic field.

Although the case where the guide 12 has a concave cross section and the slider 20 has a substantially rectangular parallelepiped shape has been described above, the shapes of the two may be interchanged. Fig. 6 is an axial cross-sectional view of the pneumatic actuator 50 according to this modification.

In fig. 6, the guide 52 has a square cross section, and the slider 70 has a concave cross section. A plurality of air pads 80 are formed on the inner surface of the slider 70 on the side opposite to the guide 52 (i.e., the upper surface 72, the side surface 74, the side surface 76). The air cushions 80 eject high-pressure gas supplied from an unillustrated air supply system to form a high-pressure gas layer in the minute gaps between the slider 70 and the guides 52, thereby floating the slider 70 from the guides 52. A pneumatic servo chamber (not shown) for driving the slider 70 is formed in the center of the slider 70.

Although not shown, an exhaust groove for differential exhaust is formed in the edge portions of the upper surface 72, the side surfaces 74, and the side surfaces 76 of the slider 70 so as to surround the plurality of air pads 80. The exhaust grooves are connected to an exhaust pump (not shown), respectively, to discharge the compressed gas supplied from the air cushion 80 and the pneumatic servo chamber of the slider 70 to the inside space to the outside. Thereby, leakage of compressed gas from the gap between the guide 52 and the slider 70 is prevented, and therefore, the pneumatic actuator can be used even under a vacuum environment. In addition, when the pneumatic actuator 50 is used in an atmospheric pressure environment, such a vent groove is not required.

In the above embodiment, the case where the magnetic biasing mechanism 48 is provided to enhance the bearing rigidity of the actuator has been described. However, instead of the magnetic biasing mechanism, a linear guide or the like may be used to structurally connect the slider and the guide in the vertical direction. In this case, it is not necessary to provide an air cushion on the slider. When the linear guide is used, the actuator can be used in both an atmospheric environment and a vacuum environment.

The configurations of the actuators according to the embodiments have been described above. The present embodiment is an example, and those skilled in the art will understand that various modifications exist in combination of the respective constituent elements, and such modifications are also included in the scope of the present invention.

According to the present invention, as the guide mechanism of the actuator, an air cushion and magnetic pretensioning mechanism, a linear guide can be freely selected. The actuator can be used in both an atmospheric environment and a vacuum environment.

In the embodiments, the case where the pneumatic actuator is made of a non-magnetic body (in particular, ceramic) has been described, but the present invention can also be applied to a pneumatic actuator made of a magnetic body.

In the embodiments, the case where the guide and the slider of the actuator have rectangular cross-sectional shapes has been described, but the present invention can also be applied to an actuator having a guide and a slider having arbitrary cross-sectional shapes.

Fig. 7 to 9 are axial sectional views of the pneumatic actuator according to the modified example. Fig. 7 to 9 correspond to fig. 3, respectively.

Fig. 7 is an axial cross-sectional view of a pneumatic actuator 110 according to a modification. The pneumatic actuator 110 includes a guide 12 and a slider 20. The slider 20 has a trapezoidal cross-sectional shape, and the 1 st side surface 24 and the 2 nd side surface 26 thereof are inclined so as to be closer to each other as they approach the upper side. The guide 12 has a concave profile corresponding to the slider 20. That is, the inner surfaces 38a and 39a of the 1 st and 2

nd side walls

38 and 39 of the guide 12 are inclined so as to be closer to each other on the upper side.

According to this modification, the same operational effects as those of the pneumatic actuator according to the embodiment are obtained. In the present modification, the 1 st side surface 24 and the 2 nd side surface 26 of the slider 20 are inclined, and the surfaces of the guides 12 facing the first side surface and the second side surface are also inclined. Therefore, the high-pressure gas layer formed in the gap between the slider 20 and the guide 12 by the gas ejected from the air cushion 30 can apply a downward force to the 1 st side surface 24 and the 2 nd side surface 26 (and thus the slider 20). That is, according to the present modification, the bearing rigidity of the pneumatic actuator is improved.

Fig. 8 is an axial cross-sectional view of a pneumatic actuator 210 according to a modification. The pneumatic actuator 210 includes the guide 12 and the slider 20. The slider 20 has a rectangular sectional shape, and the guide 12 has a concave sectional shape.

In the present modification, the 1 st side wall 38 and the 2 nd side wall 39 of the guide 12 have an L-shaped cross-sectional shape. The 1 st side wall 38 and the 2 nd side wall 39 have a 1 st extending portion 38b and a 2 nd extending portion 39b extending toward each other, respectively. In other words, the guide 12 may have an upper wall in addition to the bottom wall 37, the 1 st side wall 38, and the 2 nd side wall 39, and a part (central portion) of the upper wall may be opened. An air cushion 30 is formed on the upper surface of the slider 20 at a portion opposite to the 1 st extension 38b and the 2 nd extension 39 b.

According to this modification, the same operational effects as those of the pneumatic actuator according to the embodiment are obtained. In the present modification, the air bearing 30 is formed on the upper surface of the slider 20 facing the 1 st extending portion 38b and the 2 nd extending portion 39 b. Therefore, the high-pressure gas layer formed in the gap between the slider 20 and the guide 12 by the gas ejected from the air cushion 30 can apply a downward force to the slider 20. That is, according to the present modification, the bearing rigidity of the pneumatic actuator is improved.

Fig. 9 is an axial cross-sectional view of a pneumatic actuator 310 according to a modification. The pneumatic actuator 310 includes the guide 12 and the slider 20. The guide 12 and the slider 20 each have a rectangular cross-sectional shape. The cross-sectional shapes of the guide 12 and the slider 20 are not limited to rectangular, and may be polygonal. In the present modification, three surfaces of the guide 12 are opened.

Among the surfaces constituting the slider 20, a surface (i.e., the bottom surface 22) opposite to the guide 12 is formed with a plurality of air pads 30. Further, on the bottom surface 22 of the slider 20,

exhaust grooves

32, 34, 36 for differential exhaust are formed so as to surround the plurality of air pads 30.

According to this modification, since only the bottom surface 22 of the slider 20 is restrained, the structures of the guide 12 and the slider 20 are further simplified.

In the embodiment, the case where one pneumatic servo chamber 28 is formed in the slider 20 has been described, but a plurality of pneumatic servo chambers may be formed. Fig. 10 is an axial cross-sectional view of the pneumatic actuator 420 according to this modification. Fig. 10 corresponds to fig. 8. In the present modification, the pneumatic servo chambers 28 are formed in the 1 st side surface 24 and the 2 nd side surface 26, respectively. That is, the two pneumatic servo chambers 28 are formed so as to face the inner surfaces 38a and 39a facing each other with the slider 20 interposed therebetween. According to this modification, even if pressure fluctuations occur in the two pneumatic servo chambers 28, the force generated by the pressure fluctuations can be cancelled out by the two pneumatic servo chambers 28. Therefore, even if pressure fluctuations occur in the pneumatic servo chamber 28, the pressure fluctuations can be suppressed from affecting the gap between the slider 20 and the guide 12.

Description of the symbols

10-pneumatic actuator, 12-guide, 20-slide, 30-air cushion, 34-exhaust groove, 44-magnet, 48-magnetic pretensioning mechanism, 50-pneumatic actuator, 52-guide, 70-slide, 80-air cushion.

Industrial applicability

Claims

1. An actuator, comprising: a guide extending in one direction; a slide movable in an axial direction with respect to the guide, said actuator being characterized in that,

a portion of at least one face of the guide is open,

the slider is configured to have an air cushion which is surrounded by a plurality of exhaust grooves and ejects compressed gas, and a pneumatic servo chamber for driving the slider, and the slider is guided by the guide member in a state of being floated from the guide member,

the guide and the slider are made of a non-magnetic material.

2. The actuator of claim 1,

the guide has a concave cross section, the slider is configured to be constrained by three surfaces constituting the concave cross section, and the slider is guided by the guide in a state of being floated with respect to the guide.

3. The actuator of claim 1,

the slider has a square cross section, is configured such that at least three surfaces of a plurality of surfaces constituting the square cross section are restricted, and is guided by the guide in a state of being floated with respect to the guide.

4. An actuator according to any of claims 1 to 3,

the vent groove includes a portion extending in the axial direction.

5. The actuator of claim 1,

the slider has a square cross section, is constrained on four surfaces among a plurality of surfaces constituting the square cross section, and is guided by the guide in a state of being floated from the guide.

6. An actuator, comprising: a guide extending in one direction; a slide movable in an axial direction with respect to the guide, said actuator being characterized in that,

the slider is configured to have an air cushion and a plurality of pneumatic servo chambers, one surface of which is open, and which are surrounded by a plurality of exhaust grooves and which discharge compressed gas, and the slider is guided by the guide while being floated from the guide,

the guide and the slider are made of a non-magnetic material.

7. The actuator of claim 6,

the guide having a square cross-section, the slider having a concave cross-section,

the guide is disposed on an inner surface side of the slider.

8. An actuator, comprising: a guide extending in one direction; a slide movable in an axial direction with respect to the guide, said actuator being characterized in that,

a portion of at least one face of the guide is open,

the slider is configured to have an air cushion and a plurality of pneumatic servo chambers, which are surrounded by a plurality of exhaust grooves and eject compressed gas, and is guided by the guide member in a state of being floated from the guide member,

the actuator is also provided with a magnetic force mechanism,

the guide and the slider are made of a non-magnetic material.

9. An actuator, comprising: a guide extending in one direction; a slide movable in an axial direction with respect to the guide, said actuator being characterized in that,

a portion of at least one face of the guide is open,

the actuator is further provided with a linear guide mechanism,

the guide and the slider are made of a non-magnetic material.

10. An object stage device, characterized in that,

an actuator according to any one of claims 1 to 9.

11. An exposure apparatus, characterized in that,

the stage device according to claim 10.